The present invention is concerned with treatment of hypertension using certain tripeptides of the thyrotropin releasing hormone type.
Thyrotropin releasing hormone (TRH) is a known tripeptide, L-pyrogulutamyl-L-histidyl-L-proline-NH.sub.2, having thyroid stimulating, antidepressant and lactation promoting activities [U.S. Pat. No. 3,931,139; Science, 178, 417-418 (1972)]. A series of TRH analogs are disclosed in U.S. 3,050,248. These analogs include oxopiperidin-6-ylcarbonyl-histidyl-N-thiazolidinylcarboxamide tripeptides. Other derivatives and analogs of THR are disclosed in "Chemistry and Biology of Peptides", Proceedings of the Third American Peptide Symposium, pages 601-608, Ann Arbor Science Publisher Inc., Ann Arbor, Mich. (1972); Belgian Pat. No. 832,783 and U.S. Pat. No. 3,931,139. There is no suggestion in the prior art of any antihypertensive activity for either TRH or its analogs and derivatives.
It has been discovered that certain of these tripeptides do have antihypertensive activity and may be useful for treating hypertensive patients.